I couldn't be happier with this product. I have an 11-year-old shih Tzu and I can tell that it was getting hard for him to jump up on things and he seemed like he wasn't completely himself. He's been on these for a little over a month, he is jumping up like a champ, I can see a huge difference. Thank you LifeSource vitamins, I'm going to try a few of the other dog vitamins that you have.